I did a sour butternut squash brown a couple years ago. I was happy with the results, but the squash flavor was subtle at most. It was inspired by Alpine's sour wine barrel aged pumpkin beer, Ichabod. I’d keep the spicing subtle, and add as much pumpkin as you want,.

The spice was the neat part with the sour. It seem to work pretty well. Neither of these had too much funk just mostly lactic acid sourness. I'm not sure I'd like 5 gallons, but if you like pumpkin beer than maybe you will.

I realize it's probably too late to sour a pumpkin ale for this year. I was thinking about possibly making a 10 gallon batch though, having having 5 gallons un-soured this year, and then souring the other 5 for next year...

To be honest though, I'll probably split it into two batches because I think the sour recipe will be a bit different than the normal one. I may keep the recipe the same though, and just vary the amount of spice mix added to each one??? Either way, I'll probably split them up into two batches.